1. Field
The present disclosure relates generally to ion implantation and, more specifically, to lower dose rate ion implantation using a wider ion beam.
2. Related Art
Ion implantation is a process used in fabricating integrated semiconductor devices whereby impurities are introduced into a work piece. During ion implantation, an ion beam may be extracted from an ion source and filtered by mass, charge, and energy through a magnetic analyzer before being directed to the work piece. In conventional ion implantation processes, the ion beam may typically be optimized to maximize the beam density, thereby maximizing dose rates and enabling higher throughput. For example, the ion beam may be extracted from the ion source under conditions that maximize the ion beam current. Further, the ion beam may be shaped and focused to form a narrow concentrated ribbon-shaped beam having high beam density.
As semiconductor manufacturers continue to shrink the dimensions of semiconductor devices, the current generation of semiconductor devices may be increasingly sensitive to ion implantation at high dose rates. In particular, ion implantation at high dose rates may cause significant device damage and yield loss. One method of reducing the dose rates may be to increase the scan speed of the work piece relative to the ion beam. However, adjusting the scan speed alone may not be sufficient to reduce device damage to an acceptable level.